Liquid seal device for regulators



Aug. 8, 1933. A, D MacLEAN AL 1,921,366

LIQUID SEAL DEVICE FOR REGULATORS 5 /IEI-l:

Filed Deo. l5 1930 Patented Aug..` 8, 17933 Y" PAT-Er oFrCEi y unirse STATES,

` Llamo SEAL DEVICE Fon aEGULA'rons Allen D. lvlaclllean and Charles B.- Johnson, Pittsburgh, Pa., assignors to Pittsburgh Equitable Meter Company, Pittsburgh, Pa., a ration of Pennsylvania s Application YDecemlnrer 13,1193'0 v, serial No. 502,200

'7 claims. l(c1. 137-53) This invention relates to a liquid sealing device, and particularly/.to a liquid seal for use with gas regulators, although not limited to such use; and isa continuation in part of our earlier application,.Serial Number 411,697 filed December 2,3.1929 and entitled.Liquid seal device for regulators.. It discloses .certain modifications and improvements of thedeviceas described in thatv vices as. pressure regulators and meters are employed'it is usually necessary to .provide safety devices to afford relief inthe case of excessive VFigure pressures. Liquid seals as constructed priorr to our invention'have-been so corntructedv that when a,..blow ott occurred., considerable of the sealing liquid vwas blown on' and lostjThis required the frequent replacementofy the lost liquid in order to maintain`the seal in accurate and complete `working operation. We have provided improved constructions inwhich the sealing liquidwhen blown out is collected and prevented from being expelledirom the seal device.

In prior liquid seals it has been customary to pour in the sealing liquid, as for example mer-V cury, on the job, when the seal is installed and after some of the sealing liquid has been blown out and lost, thus decreasing the effectiveness and accuracy oi the seal. This necessitates the mechanic following instructions regarding the quantity of liquid to be poured in withgreat care, since if an incorrect quantityA is poured inin changing the seal the device is rendered inacv curate and. insensitive to the gas pressure. Human verrork enters into the process andan accurate, sensitive and proper functioning of the seal cannot in allcases be obtained. i

It is a further object oi lourinvention vto provide a liquid seal in which a shipping cartridge or container is used. Such container is supplied combined outlet connections and liquid seals for the low pressure side of a gas regulator, adapted to conveniently control a supply of gas to` one In fluiddistribution Awhere now controlling de or more lowv pressure pipes from a common high pressure source.

We have provided a liquid seal that is inexpensive, easy toinstall, sensitive and readily responsive to the gas pressure and yet isextremelydurablein construction.

These and further objects will be apparent from the following description kand from the Y scope ofthe appended claims when taken in connection with the accompanying drawing wherein: Y

Figurel is a longitudinal section of one form of completeA seal embodyingA our invention.

' Figure 2 is a top view of the seal shown in Figure 1. l

vFigure 3 is a longitudinal section' of.. a slightly modified form of ourseal.'

Figure l is a top view of the seal shown in Figure 5 is a sectional view of the shipping cartridge provided for attachmentV to our im' proved seal.. .Y Y

Referring to the drawing and particularly to Figure 1,'Ja preferred embodiment of our improved seal includes a body portion 1 having a threaded nipple 2,thereon, for detachable association with a gas regulator or other Vdevice requiring a` liquidseal. The body portion 1,7,as shown, includes aV hollow central casing 3 with internally threaded branches ll and 5 radiating therefrom. These branchesv l and 5fare adapted for'connection to the low pressure mains protectedby the pressure regulator as shown, there are only two'passages fl and 5 for connection to lowpressure mains, but obviously the invention isnotlirnited to two mains and three orfour mains couldlbe associatedv withf'the body'portion 1. When onlyone pressure mainl isV to be serviced,y the vremaining openings` 4;. and 5V are closed by pipe `plugs, which block'offthe untherewith a depending chambery 7 which com# municates with the central chamber 3 bya kthreaded bore 8. The lower portionV of chamber '7 lis contracted and has a threaded bore 9 formed thereon. Upon thisl threaded portion; y"9, screwed Vthe lower sleeveV portion 10 which is itselfformed'v with an internally threaded bore portion ll. depending chamber .7' is adapted to receive the upper end oi elongated pipe 12l which is screwed into the bore. vThis pipe passesV freely through Vtheopening ,in'lower threaded portion v9 'ofl the` chamber '7 and freely throughthreaded bore portion 11 of thesleeve V10.- Pipe 12 is openat its lower endY andis cutv at the lower end at an acute'anglefto its directionr of length as shown at113 so that some points on'the annular endsurface;,1.3 ,ofthe pipe are further from the uppery isv This threaded boreA portion 8'of the Cil annular end surface of the pipe, than others. The purpose of this construction will be described later.

Pipe 12 is surrounded by a second conduit or pipe 14 of larger diameter than pipe 12 and thisY pipe has threads formed thereon and is adapted to be screwed into bore portion 11 of sleeve 10. Since this pipe is larger in diameter than pipe 12 an annular space is provided. between the pipes when the seal is assembled the purpose of which will be described hereinafter. The lower end of pipe 14 is closed by a cap 15 which is screwthreadedly engaged thereon and preferably welded in place.

As seen from Figures 1 and 2 the chamber '7 is provided with a plurality of vent holes 16 to provide for the escaping of the gas out of the seal to the outside atmosphere. The sides of chamber '7 are formed of an upper curved wall 1'? and a lower curved wall 18. It will be noted that sleeve 16 provides, because of its fiowing sides 19, a cavity or chamber 2O which communicates with chamber '7, only through the narrow bore 21 in the v member '7. Thus communicating opening 21 forms a constricted opening between the two chambers. v

Pipe 14 may be readily detached from'the remaining portions of the seal by merely unscrewing it from the bore 1l', and is used as a shipping cartridge or container for the desired quantity of liquid,'us'ually mercury, as shown in Figure 5. The pipe is filled with the correct quantity of sealing liquid at the factory, and is closed by a removable cap 22 in which a leather or rubber washer 23 may be interposed if found desirable. Thus the mercury or other sealing liquid is securely retained within the pipe during shipment. When so used the correct quantity of liquid may be inserted at the factory and shipped to the installation without danger of the loss of any of theliquid. When the device is installed for service the desired quantity of liquid is already in the seal and it is not necessary for the mechanic to pour out any measured quantity of liquid.

The immense practical utility of this shipping cartridge containingthe exact quantity of sealing iiuid for sensitive and accurate operation will be readily appreciated, for should any of the sealing liquid be lost all that is necessary is for the user to have an extra cartridge on hand and insert it, since the cartridges are all interchangeable. The householder may be provided with one or more service cartridges, such as shown in Figure 5, with simple instructions to close the valve leading to the low pressure main, remove the old cartridge 14 and insert a fresh cartridge whenever the liquid therein has become lost for any reason.

The design of chambers '7 and 20 is such that possibility of loss of the sealing liquid, usually mercury, is eliminated almost entirely in the event of an excessive pressure on the low pressure main.f The liquid is forced down by the excess pressure from chamber 3 forcing the liquid upwardly in the annular space between pipes 12 and 14, throwing this liquid upwardly into chamber 20. Before the liquid can find its way'into chamber '7 it must pass through constricted opening 21 and thus will be done only with considerable diiiiculty as the narrow channel acts as a baffie to free passage of the fluid. After it iinds its way into chamber 7 it is deflected by the baiiling side walls17 and 18 and the possibility of the escape of the sealing liquid out of the device through vents 16, which vents are disposed substantially laterally of the restricted passage 21 so that liquid thrown violently through said restriction against the portion of the wall 17 directly thereabove will not be thrown through said vents. Loss of liquid is thus prevented. Ample space in the chamber 18 is provided for the reception of the liquid while the pressure of the gas is being relieved by flow thereof through restriction 2l and vent 16. When the excessive pressure has been relieved the mercury or other sealing liquid will flow back through opening 21 and. annular space between pipes 12 and 14 and will automatically reset the seal for future operation.

In the modification shown in Figures 3 and 4, the two castings 7 and 10 are replaced by a single member. This member is formed at the upper portion with internally threaded branches 4 and 5 as in the first described modification and includes the same hollow central casing 3. A plug 6 is also shown closing one of the threaded branches. A lower threaded bore 9 is also formed on 'this unitary member. The hollow central chamber 3 communicates with another chamber 24 formed in the casing by means of a threaded bore 8. The pipe 12 is screwed into the threaded bore 8 and extends through chambers 24 and 23 and through threaded bore 9 on the member 22. Pipe 14 of larger diameter than pipe 12 surrounds pipe 12 as in the iirst described modification and this pipe is securely screwed into the threaded' bore 9 on casting 22. .The diiierences in the pipe diameters providean annular space 25 between the pipe members. The lower end oi pipe 12 is cut atan acute angle to the direction of its length, as shown at 13, the same as in the previously described form. The casting 22 is provided with a plurality of holes or vents 25 leading from chamber 24 to the outside Vatmosphere. The chambers 23 and 24 formed in the casting 22 are in communication through a narrow constricted opening 26 through which pipeY 12 passes, leaving an annular opening surround.- ing this pipe. The lower end. of pipe 14 is closed by a plug 2'7 preferably Welded in place, and this pipe may be closed at its upper end and used as a shipping cartridge as the pipe shown in the first described modication and illustrated at Figure 5. As in that modiiication the sealing liquid when blown upward by an excessive pressure on the low pressure main, will travel upwardly through chamber 23 and in order to get to chamber 24 will have to pass through the constricted annular opening 26. The narrowness of this opening will retard the'force movement of the sealing liquid and in this way lossof the liquid through the openings 25 is prevented. The gas under the excessive pressure passes out through openings 25 into the outer atmosphere.

It is believed that the operation of the device will be obvious from the above description. Due to pressure within the pipe 12 the liquid contained therein will be forced downwardly out of the open lower end thereof, and up into the annular space between the pipes 12 and 14. If excessive pressure occurs the liquid is blown up- `or essential characteristics thereof. The presany of the sealing liquid find its way into chamber 7 it is deflected by'baffling side walls 17 directly in its path and thus further prevented from being dispelled through the laterally disposed apertures 16 as above stated. In the modication of Figure 3, it will be noted that the wall directly above the restriction 26 is vimperforate and that the vents 25 extend in a direction transverse tothe direction in which the liquid that passes restriction 26 is blown. The course of said liquid is checked and said liquid drops upon the inclined surface leading toward. restriction 26 asillustrated. When the excessive pressure has been relieved the sealing liquid ilows back through annular openingsr21 or 26 into the annular space between pipes 12 and 14 and so automatically resets the seal.

mined. Thus when a new shipping cartridge is` sent out to the installation,1all that is necessary for the workman to d oto accurately `and correctly set the seal, is to insert the shipping cartridge pipe 14, after removal of the cap 21, until it will not go in any further by reason of abutment against lowermost edge'of pipe 12. It is then assured that the mercury shall stand at exf actly the same height in the annular space between pipes 12 and 14 at all times, since the cartridge is shipped out always containing thesame and correct quantity of the sealing fluid. In addition this construction of the lower end of pipe 12 insures that there is no dead or waste space be-v tween the lower end of pipe 12 and the cap or closure for the lower end of pipe 14. This space would necessitate the use of a greater quantity of mercury than necessary and by this construction this is avoided.

The distinctly practical and novel advantages presented in our invention as Yherein disclosed' will be apparent. The seal is one in which the loss of the sealing fluid in the event of an excessive pressure or blowoff is greatly minimized by the chamber construction, if not'entirely prevented. In addition when a blowoii has occurred,

the seal automatically resets itself since the sealing fluid flows back into sealing. position again. The VVshipping cartridge provision, which entirely eliminates the necessity for the installation mechanic measuring or pouring the fluid on the job is an important and novel advantage, ksince it insures the correct amount of fluid for accurate operation at alltimes. In addition should any of this fluid become lost through inadvertence or breakage, it is a simple step to replace the pipe 14 by a similar cartridge unit. A unit may thus be kept on hand for such emergencies. The novel construction of lower end of the pipe 12 insures a minimumV quantity of the sealing fluid, which is usually an expensive liquidsuch as mercury,A since there'is no waste or dead space in the cap. In addition the end construction of pipe l2 provides for the easy and accurate positioning of cartridge 14 in the threaded bore and in the seal for correct operation.

'Ihe' inventionv may be embodied in other specific forms without departing from the spirit ent embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intendedto be embraced therein.

What we claim as new and desirevto secure by United States Letters Patent is:

1. In a liquid seal for fluid pressure regulators or the like, a pair of conduits forming therebetween a longitudinally extending annular channel for the sealing liquid, a body member formed with vent holes for the escape of the fluid under predetermined conditions and with two chambers for the reception of sealing fluid expelled under those conditions, the said chambers having means whereby escape of the sealing liquid through the vent holes is positively prevented, one of said conduits passing through both chambers and forming a constricted opening around the conduit and between said'chambers.

I 2. The construction claimed inclaim 1 Wherein the meansV for the prevention of the escape of the sealing liquid comprises a boss formed in said body member.

3. The construction claimedv in claim 1 wherein the means for the prevention of the escape of ythe sealing liquid comprises a perforated baille member through which said last mentioned conduit extends, and which provides an inclined sur-l member to provide a constricted passage, said pipe having an open lower end and projecting Vdownwardly beyond said lower chamber; means associated with said body member providing a lluid-tight housing and completely surrounding, but spaced from7 the walls of the projecting end of said pipe, and venting means associated with one of said chambers.V Y

5.Y The devicedescribedin claim 4 wherein said baille member is integrally formed with said body member and is provided with an upper surface that is inclined downwardly toward said pipe.

6. The device'described in claim 4, wherein said body member comprises two overlappingV body-forming elements and said baille member is integrally formed with one of said body-forming ,elementsinthe region where the latter cooperates with the other body-forming element.

ALLEN D'. MACLEAN. cHAs. B. JoHNsoN. 

